Protesters gather at Fort Meade in support of Bradley Manning

Supporters of Bradley Manning hold a rally at the gates of Fort Meade ahead of his trial.

Supporters of Bradley Manning hold a rally at the gates of Fort Meade ahead of his trial. (Kim Hairston, Baltimore Sun)

Andrea K. Walker and Matthew Hay Brown, The Baltimore Sun

Chanting "Free Bradley Manning" and wielding signs that read "my hero" and "Americans have the right to know," hundreds of demonstrators descended on Fort Meade on Saturday to support the soldier now facing a court-martial in the largest security breach in U.S. history.

Manning, an Army private who lived in Maryland before enlisting, has acknowledged leaking hundreds of thousands of classified documents, including diplomatic cables, Iraq and Afghanistan war logs and gunsight video footage of a U.S. helicopter attack in Baghdad, to the anti-secrecy group WikiLeaks.

After 18 months of pretrial hearings, his court martial is set to begin Monday at the Army base in Anne Arundel County.

Supporters came from Philadelphia, New York and beyond to march in the wilting heat Saturday. One man dressed as Manning; others wore shirts bearing his image. Some carried umbrellas to protect themselves from the sun.

Manning, who gained access to the classified documents as an intelligence analyst in Iraq, told the military judge presiding over his case that he wanted to provoke public debate over U.S. foreign and military policy.

When WikiLeaks and news organizations began publishing the materials in 2010, government officials said the candid political assessments and battlefield information they contained would compromise U.S. diplomacy and put American lives and others at risk.

Manning's attorneys say their release endangered no one. Damage assessments the government performed after the leak remain classified, and prosecutors have argued to keep them out of the court-martial.

Manning faces charges that include violating the Espionage Act and aiding the enemy. If convicted, he could be sentenced to life in prison.

He has pleaded guilty to several lesser charges, which could bring a sentence of up to 20 years.

Manning lived with an aunt in Potomac and studied at Montgomery College before he enlisted in the Army in 2007.

He was arrested in Baghdad in May 2010 after a hacker in whom he had confided the leak went to the FBI. Manning was brought back to the United States, where he has been held since the arrest.

Members of the Bradley Manning Support Network arrived on buses from Baltimore, Washington, Philadelphia, New York and New England to rally in Manning's defense.

It is unclear how many participated. Organizers had expected 1,000 or more, but said they thought it was closer to 600 or 700. Fort Meade officials estimated a crowd of 450 to 500.

The protesters marched about a mile along Route 175 to the front gates of Fort Meade, which base officials closed for the occasion. Access to nearby neighborhoods was restricted.

Daniel Ellsberg, the former military analyst who leaked the secret Vietnam War reports known as the Pentagon Papers to The New York Times and other newspapers in 1971, rallied in support of Manning.

Ellsberg said he felt an immediate connection to Manning when he heard that the young soldier was ready to go to prison for life for what he believed.

"I have been waiting for years for someone else to say that," Ellsberg said.

Barbara Apfelbaum, a 67-year-old teacher and antiwar activist, came from New York City to show her support.

Apfelbaum said the Afghanistan and Iraq wars were started on false claims that their governments possessed weapons of mass destruction.

She called Manning a casualty of the war.

"I think Bradley Manning is a courageous, courageous young man and he exposed things the American military didn't want to believe," she said. "Or they didn't want exposed."

Tom Manzitti, 57, of Reisterstown, said the government prosecution of Manning is an example of a larger problem.

"I am tired of a government that is literally running amok over the citizens of this country," he said. "When you speak the truth, you are considered an agitator and a criminal."

Supporters have held demonstrations periodically since Manning's pre-trial proceedings began in November 2011. Base officials said they all have been peaceful and orderly.